Pointing to the truth ... Philip Ralph's Deep Cut examined the deaths of four recruits who died at the army's barracks. Photograph: Toby Farrow/Sherman Cymru Theatr/PA

Over the past few years, as attention spans started to shrink and breaking news began to dominate, there has been an explosion of verbatim theatre. Philip Ralph, the writer of Deep Cut, a play examining the deaths of four recruits at the army's training barracks in Surrey, has suggested there is a connection between a spin-obsessed government and "a form of theatre in which audiences perceive that they are getting at some kind of hidden 'truth'". It may have been boosted by New Labour, as Ralph suggests, but it has been nurtured by the secrecy and scandals that envelop individuals operating on behalf of all governments.

More and more people now appreciate what verbatim plays, this rather austere-sounding branch of political theatre, can offer.

I was initiated under Margaret Thatcher, and was astonished that in 1994 Nicolas Kent, artistic director of Kilburn's Tricycle theatre, was able to translate my edited transcripts of the arms-to-Iraq inquiry into an entertaining play. Half the Picture was performed by the most enthusiastic actors, with the prime minister of the day played by Sylvia Syms. After its Tricycle run it was shown in the House of Commons – the first time a play has been put on in the Palace of Westminster.

I began to appreciate that theatre is a tremendous platform for journalists, a medium that offers more space, more words, and more scope than newspapers and TV and radio news bulletins. Our "tribunal plays" for the Tricycle are taken from long-running public inquiries (10 years in the case of Bloody Sunday) that are treated quite superficially or incompletely in the mainstream media. Twenty-five thousand words have more impact than 250; and they become stronger still when actors are speaking them on a stage before a live audience.

Verbatim theatre, David Hare has said, "does what journalism fails to do". Robin Soans, whose plays include Talking to Terrorists and The Arab-Israeli Cookbook, has written: "The normal channels of reportage, wherein we expect some degree of responsibility and truth, are no longer reliable." Writing in Verbatim, he went as far as to say: "Only in the arts is the study of the human condition considered more important than ambition or money, so it is left to artists to ask the relevant questions." Our tribunal plays have helped to answer questions as well as pose them.

Their audiences have included many who had never previously been to the theatre. The Colour of Justice, taken from the evidence to the Macpherson inquiry into the murder of the black teenager Stephen Lawrence in 1993, continues to be performed in schools and universities and was included on the reading lists of police training colleges. Students who have come to the Tricycle have been inspired to write their own plays from public hearings, including the recent inquests into the London 7/7 bombings.

My plays have been taken from public inquiries forced on the government by evidence of wrongdoing on the part of agents of the state – police, soldiers, officials – which have either been covered up or inadequately investigated. Tactical Questioning, which opens at the Tricycle this week, is taken from the inquiry into the death of Baha Mousa, a Basra hotel worker who died in the custody of British soldiers in September 2003, and the serious abuse of other Iraqi civilians who were detained with him.

We know, or may remember, what happened to Baha Mousa; why it happened is the question the theatre can help to answer. At the same time, it can provoke further thought about the issues which led to an episode described by General Sir Michael Jackson, then head of all our soldiers, as a "stain on the character of the British army": the way British troops are trained, how their chain of command works, their loyalties, passing the buck, ministerial accountability to parliament, international law. Tactical Questioning, I believe, succinctly and dramatically contextualises the official – necessarily long – report, expected very soon, into the Baha Mousa inquiry by its chairman, the former appeal court judge, Sir William Gage.

Others, notably Hare in The Permanent Way and Stuff Happens, have mixed verbatim material from speeches or reports with original writing. Before he wrote Black Watch, a brilliantly evocative play inspired by the famous Scottish regiment's controversial deployment to central Iraq, Gregory Burke interviewed a group of soldiers who had recently left the regiment in the pubs of Fife. "I told Greg not to go away and write a fictional drama set in Iraq, but that instead we should try and tell the 'real' stories of the solders in their own words," said the play's director, John Tiffany.

Maybe pure verbatim theatre is less creative, but it lets people speak for themselves, as Tactical Questioning does, in illuminating ways, and in ways they sometimes did not intend.